A hard disk can be configured to store information. In some arrangements, a hard disk can be configured to cooperate with one or more other hard disks. A just a bunch of disks (JBOD) system usually includes one level or a multilevel extended chips to control a plurality of hard disks. The JBOD can include a power supply that provides current at the time of powering the JBOD so that the hard disks spin. When the hard disk drives execute spin up at the time of powering on, current of a power supply can experience a surge.